﻿#region License

/*
 * Copyright © 2002-2009 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#endregion

using System;
using System.Collections.Specialized;
using System.Diagnostics;
using Common.Logging.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Logging;
using Microsoft.Practices.EnterpriseLibrary.Logging.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Logging.Filters;

namespace Common.Logging.EntLib
{
	/// <summary>
	/// Filters <see cref="LogEntry"/>s by severity (see <see cref="TraceEventType"/>).
	/// </summary>
	/// <author>Erich Eichinger</author>
	[ConfigurationElementType(typeof (CustomLogFilterData))]
	public class SeverityFilter : LogFilter
	{
		private int severityMask = Int32.MaxValue;

		/// <summary>
		/// Bitmask to identify severity levels that should be logged.
		/// </summary>
		public int SeverityMask
		{
			get { return severityMask; }
			set { severityMask = value; }
		}

		/// <summary>
		/// Creates a new filter instance
		/// </summary>
		public SeverityFilter(string name, int severityMask)
			: base(name)
		{
			this.severityMask = severityMask;
		}

		/// <summary>
		/// Creates a new filter instance
		/// </summary>
		public SeverityFilter(string name, TraceEventType severityMask)
			: this(name, (int) severityMask)
		{
		}

		/// <summary>
		/// Creates a new filter instance
		/// </summary>
		public SeverityFilter(NameValueCollection attributes)
			: base((attributes != null && attributes["name"] != null) ? attributes["name"] : "Severity Filter")
		{
			this.severityMask = ArgUtils.TryParse(this.severityMask
			                                      , ArgUtils.GetValue(attributes, "SeverityMask"));
		}

		/// <summary>
		/// Check, if <paramref name="log"/> severity matches <see cref="severityMask"/>.
		/// </summary>
		/// <param name="log"></param>
		/// <returns></returns>
		public override bool Filter(LogEntry log)
		{
			return ShouldLog(log.Severity);
		}

		/// <summary>
		/// Checks, whether the specified severity is allowed to log.
		/// </summary>
		public bool ShouldLog(TraceEventType severity)
		{
			int evSeverity = (int) severity;

			return ((evSeverity & severityMask) == evSeverity);
		}
	}
}